Pressure-sensitive carbonless paper is well known in the art. See, for example, U.S. Pat. Nos. 2,712,507; 2,730,456; 3,455,721; 3,466,184; and 3,672,935. These papers include a developer sheet (also referred to as a CF sheet), which comprises a substrate which carries a coating containing an electron acceptor which reacts with the leuco dye transferred to the surface of the developer sheet to form an image.
One of the most typical examples of developer sheets, particularly in the U.S. market, employs a developer resin as the electron acceptor. One example of these developer sheets is described in U.S. Pat. No. 4,226,962 to Stolfo.
Conventional developer sheets often suffer from several drawbacks. The images created on the developer sheet are slow to form and are often weak in intensity. The coating compositions have a high viscosity. The developer sheets may also have a low binder concentration which decreases the surface strength and causes problems such as dusting, picks and piling.